1. Field of the Invention
The field of this invention generally relates to shoes, and more particularly to a shoe that allows air circulation.
2. Background of the Invention
Shoes are generally designed to provide protection and cushioning to a user's feet. However, many shoes may also provide an unfavorable environment for the user's feet, especially where the shoes do not allow for adequate air circulation.
A shoe that lacks adequate air circulation may be both uncomfortable and unhealthy. Improper circulation often creates excessively hot and humid conditions within shoes. Such conditions may contribute to the development of fungus and/or bacteria which may lead to discomfort and/or foot odor. In addition, the excessive heat and humidity may create further discomfort caused by blisters and/or muscle fatigue.
Shoes that provide air circulation allow for normal body cooling and prevent excessive heat and humidity within the shoes. As a result, increasing air circulation in a shoe may dramatically reduce the likelihood of the user developing fungal infections, bacterial infections, foot odor, blisters, and/or muscle fatigue.
Shoes designed to address this problem have provided only partial solutions. In one design, an elastically deformable pad is inserted in a heel portion of the sole in a shoe. Ventilation channels extend along the length of the sole from the deformable pad to a toe region. A plurality of valves are the sole from the deformable pad to a toe region. A plurality of valves are included in the channels. The valves are configured so that air is ejected from the shoe to the environment when the pad is compressed and hot air in the toe portion is drawn back to the heel portion when the pad is decompressed. The hot air can then be ejected with the next pad compression.
Another ventilated shoe design includes a sole that incorporates lateral openings and a compressible insert in a heel portion. A gasket that is permeable to air but not to water is interposed between the lateral openings and the insert. The heel insert includes ducts that communicate with ducts that extend through the area of the plantar arch and toward the toes. The heel insert is designed to act as a pump with compression and decompression caused by normal foot motion.
Yet another shoe designed to increase the air circulation in a shoe incorporates an insole, a cushion, and a midsole forming a layered structure; holes that extend through the layered structure in a forefoot region; and an outsole that includes a plurality of airways. The holes communicate with airways in an outsole. Directional valves are included that allow air within the forefoot portion to flow to the environment when a user compresses the outsole.
One simplified ventilation system for shoes incorporates holes located in an arch portion through an upper. A waterproof breathable membrane is attached to the upper and covers the holes. The shoe also includes an insole that has channels in the bottom side that are aligned with the holes in the upper so that air passing through the membrane enters the channels. Compression and decompression of the insole by the user causes the air to circulate through the channels and through holes in the insole.
The shoes described above present significant disadvantages. First, the configuration of the valves and waterproof membranes severely restrict the ability of heated, water-vapor laden air to flow through the shoe. As a result, the volume of air that is available for heat transfer and evacuation of humidity is significantly reduced. In addition, the designs are dependent on the compression of the shoe to act as a pump to force air through the shoes. Natural drafts would have virtually no impact on circulation through the shoe since they would not provide sufficient force to pass through the valves and flow through the membranes is significantly reduced.
Accordingly, there is a need for a shoe that is capable of efficiently providing air circulation throughout the shoe without requiring the sole of the shoe to be compressed.